Nick Clegg ignored, in his opening remarks, the death of Bob Crow. Perhaps that enjoyably outspoken trade unionist never bothered to attack Clegg, who was standing in at Prime Minister’s Questions for David Cameron, absent on a visit to Israel.

For Clegg does notice when he is attacked. He went out of his way to respond to criticism of him by Dominic Cummings, until recently Michael Gove’s special adviser, on the question of free school meals.

Clegg got his Lib Dem colleague, Sir Alan Beith (Berwick upon Tweed), to serve up an easy-peasy question about free school meals. This enabled the Deputy Prime Minister to condemn “the slightly inexplicable views of an entirely unknown if highly opinionated ex-party-adviser to the Conservative Party about free school meals”.

How odd to bother to attack someone if he is entirely unknown. But the thin-skinned Clegg at least deserves credit for fighting spirit, most of it directed against Harriet Harman, who was standing in for Ed Miliband.

Harman tried to rile him by asking if there is “any logic to how the Lib Dems vote other than self-interest”. Clegg responded rather well, by accusing Labour of “collective amnesia” about “the terrible suffering of the patients in Mid-Staffordshire and other parts of the NHS” while that party was in power. He also reminded the House of the dreadfully long waiting times to see a doctor in Wales, where Labour is still in government.

The Deputy Prime Minister enjoyed pointing out that Labour had kept the top rate of tax at 40 pence for 13 years. And he said Labour had given “a kick in the teeth” to young people who are trying to get apprenticeships.

Harman possesses admirable courage and fighting spirit: her style made a refreshing change to Miliband’s clever but somehow less than wholehearted observations. But her directness got her nowhere, for it just elicited a similar directness from Clegg. It is difficult to imagine the Lib Dems under his leadership doing a deal with the Labour Party.

Kevin Brennan (Lab, Cardiff West) referred to the recent victory in a council election in Nottingham of a Bus Pass Elvis Party candidate over a Lib Dem, and suggested Clegg himself could be described by paraphrasing a song by the original Elvis: “You ain’t nothin but a lap dog.”

Clegg could not on the spur of the moment think of a joke to counter that, but said: “At least we’re not the lap dog of the bankers.” He added several more lines of abuse of Labour. Having flattered Cummings by taking him too seriously, he was now flattering Brennan.

But although Clegg’s bark may be worse than his bite, at least he has a bark. It may be said of our multilingual Deputy Prime Minister: